A new reactive sputtering technique for the low temperature deposition of transparent light emitting ZnS:Mn thin films

Abstract

The temperature sensitive nature of the substrates used in the flexible displays market necessitates a low temperature deposition technique for processing them. ZnS:Mn exhibiting high intensity photoluminescence and good crystallinity has been deposited onto Si wafers, glass microscope slides and polymeric substrates using a new reactive sputtering technology referred to as HiTUS. This technique enables very high deposition rates and requires no substrate heating. When incorporated as part of a complete EL device, as-deposited ZnS:Mn films are seen to exhibit stable electroluminescence on Si, glass and planarised PET substrate materials. Post annealing of the devices on Si and glass at temperatures of up to 600 °C show that the HiTUS films perform better than equivalent ZnS:Mn films deposited using RF magnetron sputtering.Copyright line will be provided by the publisher 1 Introduction This work compares two different sputtering techniques for the deposition of alternating current thin film electroluminescent (ACTFEL) devices. High target utilisation sputtering (HiTUS) is a new method for sputtering thin films that allows for the deposition of working electroluminescent (EL) structures with no substrate heating or post deposition annealing [1]. However, here we look at the effect of post deposition annealing HiTUS devices that have been deposited onto silicon and glass substrates with no substrate heating. Radio frequency (RF) magnetron sputtering has also been used for the fabrication of comparable devices with both substrate heating and post deposition annealing. The results of quantitative EL measurements for structures deposited using these two techniques are presented here.

Intrinsic photoluminescence from low temperature deposited zinc oxide thin films as a function of laser and thermal annealing

“…This yields high rate, uniform erosion of the target surface. HiTUS has been used to deposit low temperature metal oxides for transparent conducting electrodes [19], light emitting devices [20], surface acoustic wave devices [21] and thin film transistors [22][23][24].…”